The OTC Stinger double flaring toll is designed for double or single flare in copper, aluminum, soft steel brake line, and brass tubing (to 45 degrees). The chrome swivel is made of alloy steel which reduces friction and the forged yoke is made of heat-treated steel for long life and durability. The kit comes with five adapters covering sizes from 3/16 inch through 1/2 inch and 4.8 millimeters through 12.7 millimeters and a blow-molded storage case.